Young David Sanders is given a very special magnifying glass by a terminally ill neighbour, Mr Silver, who asks him to take on a life long responsibility of using the magic powers of the magnifying glass to help police solve complex crimes. The magnifying glass, which is called Focal, enables David to look back in time to see images of the the past but only for a limited period. David and his parents, Paul and Laura, agree to help David and to keep Focal's secret.

David slowly comes to understand both the power and limitations of Focal and uses it to secretly uncover details of crimes which are baffling the police. In doing so, he takes on disguises to protect his identity and the secret of Focal Justice, the name which the media have given to the person who provides incredibly detailed crime information to the police.

Books are best read in sequence.

Book Six. A wave of drug related problems in Angel Park at the high schools encourages David to get involved in tracking the drug dealers, suppliers and regional distributor. A new feature on Focal helps him track a dealer to the local supplier and from there to allow David to track the distributor back to his base in Newport. The information which David supplies to the police enables them to close down the entire drug network.